I have TomTom 5 running fine on my netBook Pro. I installed GAPI from wincesoft.de first and this is used when I run TomTom. See
http://www.wincesoft.de/html/gapi_for_hpc_s.html
As I recall, all that was then required was the TomTom activation code process.
I would caution that the netBook Pro screen isn't really bright enough for easy daytime use in a car.